I've looked at many different profiles and noticed that the percentiles change drastically from person to person. Logical-Master is in the "lead", being placed in the hundred percentile, yet only holds an 82.28% win ratio; people like SportsGuru and Burningpuppies101 hold a perfect win ratio, yet remain in a lower percentile. How does this work?

Win ratios and percentiles are like a roller coaster on this site; they go up and down quite often (most often in an accordance to the number of people who have an agenda). Moral of the story: It's simply not worth the trouble taking this system seriously.